A self-ballasted lamp using LED elements as a light source may be interchangeable with an incandescent lamp. In the self-ballasted lamp, a substrate is mounted on one end surface of a base body, and a globe is attached to one end of the base body. LED elements are mounted on the substrate to form a light source. The globe covers the light source.
Generally, the incandescent lamp has wide-angle light distribution performance with high luminous intensities in an optical axis direction and a direction orthogonal to the optical axis direction. However, the self-ballasted lamp has light distribution performance with high luminous intensity in an optical axis direction opposite to a front surface of the light source and luminous intensity in a direction orthogonal to the optical axis direction. Accordingly, the self-ballasted lamp is unsuitable for some kinds of lighting fixtures.
For some applications it is desirable for the self-ballasted lamp to have wide-angle light distribution performance with high luminous intensities in an optical axis direction and a direction orthogonal to the optical axis direction, similar to an incandescent lamp. Although the globe covering the light source in the self-ballasted lamp is frequently diffusive, the diffusion by the globe may not improve luminous intensity in the direction orthogonal to the optical axis direction to a sufficient degree.
To address this issue, a self-ballasted lamp may include a lens facing a light source arranged to reflect light, which advances from the light source in an optical axis direction, in a direction orthogonal to the optical axis direction so that luminous intensity in the direction orthogonal to the optical axis direction is increases.
However, when a lens is used for a self-ballasted lamp, the lens cannot be easily arranged to face a light source, and a positional relationship between the lens and the light source cannot be adjusted. Therefore, uneven light distribution performance may be observed.
It is an object of the present invention to provide a self-ballasted lamp which can easily arrange a lens facing a light source, adjust a positional relationship between the light source and the lens, and stabilize light distribution performance, and a lighting fixture using the same.